Differential diagnosis of pancreatic cysts: A prospective study on the role of intra-cystic glucose concentration

Background: The accuracy and costs of current diagnostic methods in the differential diagnosis of pancreatic cystic lesions still has ample room for improvement. Aims: The aim of the study was to confirm the diagnostic yield of intracystic glucose in the diagnosis of pancreatic cyst subtypes. Methods: We prospectively recruited all patients who underwent Endoscopic Ultrasound with Fine Needle Aspiration of pancreatic cyst at our Institution. Results: Fifty-six patients were included in the study. We found that intracystic glucose concentration < 50 mg/dL was significantly more sensitive than a concentration of Carcinoembryonic Antigen > 192 ng/mL (93.6% vs 54.8%; p = 0.003) for the diagnosis of mucinous cysts. In terms of specificity, the two markers were not different (96% vs 100%; p = 1). Regarding the diagnosis of non-mucinous cysts, intracystic glucose concentration ≥ 50 mg/mL showed higher sensitivity than Carcinoembryonic Antigen level < 5 ng/mL (96% vs 72%) although a statistical significance could not be reached (p = 0.07). The two markers were not statistically different in terms of specificity (93.6% vs 87.1%; p = 0.62). Conclusion: Given its diagnostic performance and ease of measurement, intracystic glucose may replace Carcinoembryonic Antigen in the differential diagnosis of mucinous versus non-mucinous pancreatic cysts.